The team led by Skoltech Professor Artem R. Oganov studied the structure and properties of ternary hydrides of lanthanum and yttrium, and showed that alloying is an effective strategy for stabilizing the unstable phase of YH10 and LaH6, and is expected to become a high-temperature superconductor. The research was published in the journal "Materials Today".

Prior to the prediction of H3S in 2014, cuprates had long been record-breakers of high-temperature superconductivity. It is estimated that this unusual sulfide has high-temperature superconductivity at 191-204 K, which was later obtained through experiments, setting a new record of superconductivity.

After this discovery, many scientists turned to super hydrides, which are abnormally rich in hydrogen, and discovered a new compound that becomes superconducting at higher temperatures: LaH10 (predicted and experimentally proved to be at a pressure of 2 million atmospheres at 250- Superconductivity at 260 K) and YH10 (predicted to be a higher temperature superconductor). Despite the similarities between yttrium and lanthanum, YH10 proved to be unstable, and no one has successfully synthesized it in pure form so far. After reaching the upper limit of the critical temperature of binary hydrides, chemists turned to ternary hydrides, which seemed to be the most promising way to achieve higher temperature superconductivity. Finally in 2020, after more than 100 years of research, scientists will be able to synthesize the first room temperature superconductor-ternary sulfur and hydrocarbons? The critical temperature is +15 oC.

In their most recent work, scientists from Skoltech, the RAS Institute of Crystallography, and the VL Ginzburg High Temperature Superconductor and Quantum Materials Center studied the ternary hydrides of lanthanum and yttrium, which have different ratios.

Although lanthanum and yttrium are similar, their hydrides are different: YH6 and LaH10 do exist, but LaH6 and YH10 do not. We found that both structures can be stabilized by adding another element. For example, LaH6 can become more stable by adding 30% yttrium, and its critical superconducting temperature is slightly higher than that of YH6, Professor Oganov said.

In addition, the research helps to clarify the general overview of the superconductivity of ternary hydrides. We realize that compared with binary hydrides, the ordered structures of ternary and quaternary hydrides are less and less, and the width of the superconducting transition is much larger. In addition, they require more intense and longer laser heating than binary hydrides, explained the lead author and Skoltech PhD student Dmitrii Semenok.

Scientists believe that the study of ternary hydrides has great hope for stabilizing unstable compounds and enhancing their superconducting properties.